Sequence counting and locking circuit



1 H. R. SHILLINGTON 2,968,747

SEQUENCE COUNTING AND LOCKING CIRCUIT Filed Jan. 6, 1959 Patentecl Jan.17, 1961 2,968,747 SEQUENCE COUNTING AND LOCKING CIRCUIT Harry R.Shillington, Glen Ellyn, Ill., assignor to Western Electric Company,Incorporated, New York, N.Y., a corporation of New York Filed Jan. 6,1959, Ser. No. 785,292 4 Claims. (Cl. 317-139) This invention relates toa sequence counting and locking circuit and more particularly to alocking circuit which upon ascertainment of successive switch closuresin a predetermined sequence functions to control external circuitry.

The subjection of articles to successive testing or manufacturingoperations at numerous diverse locations has in the past required anextensive amount of costly handling and scrutinization of articlesundergoing the various operations. To eliminate these problems, it ishighly desirable to provide a circuit which will be rendered effectiveby successive satisfactorily completed operations at several.utilization stations and which will give notification of anyunsatisfactory conditions disclosing, at the same time, whereat themalfunction occurs. It is also desirable that a circuit of this type,upon completion of a satisfactory cycle of operation, be adapted torender external circuitry effective.

It is a prime object of this invention to provide an improved sequencecounting and locking circuit which may be utilized to control externalcircuitry.

A further object of this invention is to provide a sequence counting andlocking circuit which may be adapted to function in cooperation withnumerous external utilization stations.

Still another object of this invention is to provide a sequence countingand locking circuit with indicating devices that function to givenotification of an unsatisfactory condition at an utilization station.

A more finite object of this invention is to provide a locking circuitwhich is rendered effective to operate other instru-mentalitiessubsequent to a series of switch closures resulting from thesatisfactory operation of a plurality of external utilization stationsin a predetermined sequence.

With these and other objects in view, the present invention contemplatesa locking circuit comprising two or more series of three relays each.The first or control relay of each series is momentarily energized by aswitch closure resulting from the actuation of a cam which, in turn, iscontrolled by the satisfactory completion of an operation at autilization station. The momentary ener-- gization of this first relayin turn results in the energization of the remaining two relays whichare locked in an energized state. Upon application of power to thecircuit, a starting relay is energized which precludes the functioningof one of the Series of relays until the locking relays of the otherseries have been energized. The operation of the second or subsequentseries of relays completes the locking circuit and results in a switchclosure which may be utilized to render other instrumentalitieseffective.

Other objects and advantages of the present invention will be apparentfrom the following detailed description when considered in conjunctionwith the accompanying drawing wherein the single figure is adiagrammatic view of a sequence counting and locking circuit forming oneembodiment of the invention.

Referring to the drawing, there is disclosed a DC.

source 10 which supplies power to the circuit upon closure of a startingswitch 11. Closure of switch 11 provides a path for energizing currentthrough a conductor 12, a resistor 13, a starting relay 14 and back tothe source 10 through a reset switch 15. The energization of relay 14draws up contacts 16 and results in the opening of a circuit to thewindings of a relay 17.

A pair of utilization stations A and B are provided and controlcam-operated switches 21 and 22. The utilization station A, which may beeither a testing or manufacturing device, momentarily closes thecam-operated switch 21 after satisfactorily completing a cycle ofoperation. The closure of the switch 21 completes a path for currentfrom the conductor 12 through the switch 21, a resistor 23 and a relay24 to the source 10. The energized relay 24 momentarily draws upcontacts 26 thereby completing a circuit from the source through thecontacts 16 and 26 and a contact 27 of a relay 28 to a relay 29.Energizing current to the relay 29 results in the drawing up of contacts31 thereby opening the locking circuit to the relay 14- and at the sametime completing a locking circuit to relays 28 and 29 for retaining therelays in an energized state after the cam-operated switch 21 reopens. Apath of energizing current for the relay 28 may be traced from thesource through the relay 29, the relay 28, a low-resistance indicatinglamp 32, contacts 31 and the reset switch 15.

Upon satisfactorily completing a cycle of operation of the utilizationstation E and with the contacts 16 returned to a former position as aresult of the deenergization of relay 14, the utilization station Brenders the cam-operated switch 22 effective resulting in theenergization of the relay 1'7 and the drawing up of contacts 33.Energizing current to the relay 17 passes from the conductor 12 throughthe switch 22, the relay- 17 and the contacts .16 to the source 10.Closure of contacts 33 provides a path for current from the source 10through a relay 34, a resistor 36, contact 37 of a relay orelectromagnet 38, and the contacts 27 and 33.

The energization of relay 34 draws up contacts 39 and provides a directpath for current from the source through the reset switch 15 and thecontact 39 to the relay 38. Energization of relay 38 results in thedrawing up of contacts 37 and locks up the entire relay networkexcluding relays 14, 17 and 24. In addition, the energization of relay38 results in the closure of a switch 41' which may be utilized tocontrol the operation of any external device C.

Mode of operation The sequence counting and locking circuit isconditioned to function in a predetermined sequence subsequent to theclosure of the starting switch 11. The momentary energization of a relay17 and the energization and locking up of relays 34 and 38 controlled bythe operation of the cam-operated switch 22 after that of relay 24 andrelays 28 and 29 under the control of the switch 21 is guaranteed by theopening of the coil circuit of the relay 17 as a result of theenergization of the relay 14 and the drawing up of contacts 16.Irrespective of when the starting switch 11 is closed, the lockingcircuit will not function until the utilization station A has completeda satisfactory cycle of operation prior to that of the utilizationstation B.

A satisfactory cycle of operation having been completed at utilizationstation A, the switch 21 is closed and the energization of relay 24occurs momentarily. The interval of time during which the relay 24 isenergized is sufficient for the energization and locking up of relays 28and 29 to take place. This phase of the cycle having been completed andthe relay 14 having been deenergized, the circuit is prepared for theoperation of the switch 22 under the control of station B. Should therehave been some malfunction in the operation performed at station A, theindicating lamp 32 will not be lit and therefore, an operator will beapprised of this unsatisfactory condition. When the lamp 132 is lit,however, the operator is notified that the second half of the cycleunder the control of station B is in progress.

Closure of switch 22 results in the momentary energization of the .relay17. Again, a sufiicient length of time is provided so that theenergization and locking up of the relays 34 and 38 might beaccomplished. The last relay in the locking circuit to be energized isrelay 38 and the energization of thisrelay operates the switch 41. Theclosure of switch 41 may be utilized in any number of ways to controlexternal circuitry. The locking circuit having completed a cycle ofoperation and being locked in the above-described manner will require anoperator to depress the .reset button 15 in order to deenergize thelocked-up relays and condition the circuit for a subsequent cycle ofoperation.

It is to be understood that the above-described arrangements are simplyillustrative of .the application of this invention. Numerous otherarrangements, such as increasing the number of series of relays operatedby a greater number of utilization stations, may be readily devised bythose skilled in the art which will embody the principles oftheinvention and fall within thespirit and scope thereof.

What is claimed is:

1. A circuit for controlling external instrumentalities in accordancewith the sequential operation of utilization devices, which circuitcomprises electromagnetic means having a normally open contact, saidnormally open contact being connected to said external instrumentalitiesto control the operation thereof, a power supply, a first normally openrelay circuit shunting said power supply, switch means controlled by oneof said utilization devices for closing said first normally open relaycircuit to accomplish the energization thereof, a locking circuitshunting said power supply and having a normally open contact of saidfirst normally open relay circuit connected in series therewith, saidlocking circuit being energized upon actuation of said switch means andthe energization of said first normally open relay circuit, a circuitconnected to said electromagnetic means and conditioned for operation bythe energization of said locking circuit, a second normally openrelaycircuit shunting said'power supply, and switch means controlled byanother of said utilization devices to concomitantly energize saidconditioncd circuit and said electromagnetic means to close saidnormally open contact and render said external instrumentalitieseffective.

2. A sequence counting and locking circuit, which comprises apowersupply, a starting switch connected'to said power supply, astartingrelay shunting said power supply and energized upon closure of saidstarting switch, a first series .of relays, .a first switch meansconnected in series with said first series of relays for selectivelyshunting said first series of relays across said power supply, one relayof said first series having a contact :drawn up upon the energizationthereof for locking said first series of relays in an energized stateand for deenergizing said starting relay, a second series of relays,another relay of said first series of relays having a contact drawnup bythe energization thereof for conditioning said second series of relaysfor operation, a second switch means connected in series with saidsecond series of relays for selectively shunting said second series ofrelays across said power supply subsequent to the energization of saidfirst series of relays, one relay of said second series having a contactdrawn up upon the energization thereof for maintaining said secondseries of relays in an energized state, and reset means connected tosaid power supply means for deenergizing said first and second series ofrelays to condition the circuit for a subsequent cycle of operation.

3. A sequence counting and locking circuit for controlling externalinstrumentalities comprising a starting relay, first and second controlrelays, a source of potential, means for selectively shunting saidsource of potential with said starting relay, sequentially operatedswitch means for selectively shunting said source of potential with saidfirst and second control relays, a first locking circuit, means renderedeffective upon energization of said starting relay for conditioning saidfirst locking circuit for operation, means for rendering said firstlocking circuit operable upon energization of said first control relaysubsequent to the actuation of said switch means associated therewith,said second control relay being precluded from energizationconcomitantly with the conditioning of said first locking circuit uponenergization of saidstarting relay, means for interrupting theenergizing circuit for said starting'relay upon energization and lockingup of said first locking circuit, a second locking circuit, meansrendered effective by the energization of said second locking circuitfor rendering external instrumentalities effective, and means forrendering said second locking circuit effective upon actuation of saidsecond control relay subsequent to the energization and locking up ofsaid first locking circuit.

-4. A relay circuit for controlling external instrumentalities inaccordance with the sequential operation of utilization devices, whichrelay circuit comprises a source of potential, 2. starting 'relayshunting said source of potential, a starting switch interconnectingsaid starting relay and said source of potential for selectivelyapplying energizing potential to said starting relay, first and secondcontrol relays, means rendered efiective by the sequential operation ofsaid utilization devices for selectively shunting said source ofpotential with said first and second control relays, a first lookingcircuit conditioned for operation upon energization of said startingrelay, means rendered efiective by the energization of said firstcontrol relay for rendering said first locking circuit effective, asecond locking circuit, means controlled by said starting relay forconditioning said second locking circuit for operation, means renderedoperable upon actuation of said first locking circuit for deenergizingsaid starting relay thereby actuating said controlled conditioning meansfor said second locking circuit, and means actuated upon theenergizationand locking up of said second locking circuit for .renderingsaid external instrumentalities effective.

Joel Mar. 2, 1948 Shillington July 22, 1958

